• Journal of Embryo Transfer
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• v.32 no.3
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• pp.105-109
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• 2017

Autophagy is an intracellular degradation and recycling system. Oocyte maturation is dynamic process, in which various proteins should be synthesized and degraded. In our previous study, we reported the loci of autophagosome and dynamics of autophagic activity in porcine oocytes during in vitro maturation. In this study, we verified loci of autophagosome in porcine follicular cumulus-oocyte complex by detection of microtubule-associated protein 1A/1B-light chain 3 (LC3) which is the reliable marker of autophagosome. Porcine ovary including various sizes of follicles was fixed within 1 hour after collection from slaughterhouse. After fixation, immunohistochemistry was conducted on sliced ovary tissue containing various sizes of follicles by using LC3 antibody. As a result, LC3 signal was clearly detected in both cumulus and oocytes of various sizes of follicles. We also found ring shaped signal which represent autophagosome near oocyte membrane. Most of the signals in oocytes were localized nearby cellular membrane while evenly dispersed in cumulus cells. Therefore, this result suggests that autophagy occurs in porcine COCs (cumulus-oocyte complexes) at follicular stage.

• Proceedings of the Korean Society of Embryo Transfer Conference
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• 2003.10a
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• pp.3-6
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• 2003

• The Korean Journal of Malacology
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• v.24 no.1
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• pp.33-40
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• 2008

Ultastructural studies of oocyte degeneration and follicle cells in female Spisula sachalinensis are described for clams collected from Jumunjin, Gangwondo, Korea. The follicle cells playan integral role in vitellogenesis and oocyte degeneration by assimilating products originating from the degenerated oocytes (thus allowed the transfer of yolk precursors needed for vitellogenesis). The functions of the follicle cells include phagocytosis and intracellular digestion of products originating from oocyte degeneration. During the period of oocyte degeneration, follicle cells of this species probably have lysosomal systems for the breakdown and reabsorption of various phagosomes(phagolysosomes) in the cytoplasm for nutrient storage; this process has been observed in other bivalves.

• Journal of Embryo Transfer
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• v.27 no.4
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• pp.193-203
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• 2012

The development of embryos reconstructed by nuclear transfer is dependent upon numerous factors including the type of recipient cell, method of enucleation, the type of donor cell, method of reconstruction, activation, the cell cycle stage of both the donor nucleus and the recipient cytoplasm and the method of culture of the reconstructed embryos. Many of these points which have been reviewed extensively elsewhere (Sun and Moor, 1995; Colman, 1999; Oback and Wells, 2002; Renard et al., 2002; Galli et al., 2003b), here we will concentrate on main area, the production of suitable cytoplast and nuclear donor, nuclear-cytoplasmic coordination, oocyte activation, culture of reconstructed embryos, and the effects that this may have on development.

• Journal of Embryo Transfer
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• v.11 no.2
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• pp.103-109
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• 1996

The aim of this study was to evaluate the effect of recombinant bovine somatotropin (bST; Boostin-S, LG Chem) treatment with FSH (Super OV) or PMSG on superovulatory response for transvaginal ultrasound-guided oocyte retrieval (TVR) in calves. Eight Korean Native Cattle(KNC) heifer calves; 150 to 240 days old; were randomly assigned to four treatment groups: 1) FSH(75 mg); 2) FSH (75 mg) + bST(500mg) 3) PMSG(1;000 IU); 4) PMSG(1, 000 IU) + bST(500 mg). Experimental calves in group 1 (n=2) and 2(n=2) were weekly superovulated for 4 consecutive weeks with daily injection of FSH for 3days and the next day subjected to TVR session. Animals in group 3 (n=2) and 4(n=2) were weekly stimulated for 4 consecutive weeks with a single dose of 1, 000 IU PMSG. TVR was performed on 72 hours after PMSG injection. Calves in group 2 and 4 was received injection of 500 mg of bST every 10 days. At each TVR session, follicle number and size were recorded; the oocytes collected and graded according to cumulus and cytoplasm investment. Collected oocyte were determined viable oocyte according to morphological quality with granulation of oocyte and number and status of cumlulus cells. IVM and IVF were performed and assessed cleavage rate on day 3 after fertilization. A Sonovet 600(Medison, Co., Ltd) realtime ultrasound scanner with a 6.5 MHz convex transducer, fixed at the tip of 500 mm estended handle equipped with a needle guide was used in collecting oocyte. Differences between groups were analysed by chi-square test. The population of large follicle ($\geq$5 nun) and aspiration rate were not significant different among the 4 groups. But, the number of small follicles (<5 mm) and aspirated oocyte in the KNC calves treated with bST were 1.3~1.6 times higher than in KNC calves treat with FSH or PMSG alone. In conclusion, the administration of bST with FSH or PMSG at superovulation for TVR in calves was increase the nurnber of small follicle which was influenced the number of aspiratable follicle.

• Journal of Embryo Transfer
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• v.32 no.3
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• pp.111-122
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• 2017

The objective of this experiment was to explore the effects of Roscovitine (Rosco) prior to in vitro maturation (IVM) of immature pig oocyte. Brilliant cresyl blue test has been used to select the good quality of oocyte. Specifically, the effects of Rosco exposure on nuclear and cytoplasmic maturation, diameter, intracellular glutathione (GSH) and reactive oxygen species (ROS), and embryonic development after parthenogenetic activation (PA) and somatic cell nuclear transfer (SCNT), and gene expression levels in SCNT embryos have been measured. Cumulus oocyte complexes (COCs) have been exposed in $75{\mu}M$ of Rosco for 22 and 44 h. The COCs that were matured in the IVM for 44 h without Rosco used as control group. Diameter of matured porcine oocytes 44 h culture with Rosco was significantly lower than 22 h culture with Rosco and control groups. GSH was higher in control group than 22 h and 44 h with Rosco but reduction of ROS in 22 h than 44 h with Rosco. In PA, exposure with Rosco 44 h oocytes group has been significantly lower than 22 h and control group in rates of maturation, cleavage and blastocyst formation. Similarly, in SCNT embryos rates of maturation, cleavage and formation of blastocyst have been also significantly lower in 44 h Rosco treated group than other two groups. SCNT embryos treated with Rosco 22 h showed greater expression levels of POU5F1, DPPA2 and NDP52Il mRNA compared with other two groups. Our results demonstrate that Rosco treatment with 22 h prior to IVM improves the development competence of porcine oocyte.

• Journal of Embryo Transfer
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• v.9 no.1
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• pp.73-83
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• 1994

The objective of this study was to develop an effective in vitro production system capable of obtaining more porcine embryos from immature oocytes. These experiments were thus conducted to examine the effect of oocytes type and maturation time on the in vitro maturation(IVM) and fertilization(IVF) of oocytes and the in vitro development (IVD)of IVF embryos. 1. The degree of oocyte maturation based on cumulus expansion index(GEI) did not differ for A- and B-typed oocytes but the index of oocyte type C was lower(P<0.05) than that of other oocyte types. 2. When the oocytes of type A and B were matured for 36, 42 and 48hrs, the GEl was not different between the 36- and 42-h maturation but the GEl after 48hrs was greatly lower(P<0.05) than that of other maturation times. 3. The highest cleavage rate(48.6%) of IVF oocytes was obtained from A typed oocytes and 42-h maturation but the developmental potential based on cleavage index was the highest when B-typed oocytes were matured for 42hrs.

• The Korean Journal of Zoology
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• v.31 no.2
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• pp.81-86
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• 1988

The relationship between cumulus cell expansion, cocyte maturation and metabolic cooperativitiy was investigated by using mouse and pig cocyte-cumulus complexes in vitro. Cocyte germinal vesicle breakdown (GVBD) and cumulus expansion were manipulated with hormones or reagents which increase intracellular cAMP leveL Metabolic cooperativity between oocyte and cumulus cells was assessed by determination of the fraction of radiolabelled uridine marker that was transferred from the cumulus mass to the oocyte. Uptake of uddine marker by mouse and pig cumulus mass was increased by about fourfold of basal level with the stimulation of hormones (human choriononic gonadotrophin, HCG; follicle stimulating hormone, FSH) or cyclic AMP sttmulators (3-isobutyl-1-methylxanthine, IBMX; forskolin) during culture. However, the fraction of uridine that was transferred from the cumulus mass to the cocyte (transfer ratio) was gradually decreased during culture, irrespective with the presence of hormones or stimulators. The decrease of the transfer ratio was not correlated with the state of occyte whether they have GV or not, or with the degree of cumulus expansion. In mouse complexes, HCG induced more significant reducton of transfer ratio than other treatments. These results do not support the idea that modulations of metabolic cooperativity between cumulus cells and oocytes are important for the regulation of meiotic resumption in mammals.

• Proceedings of the Korean Society of Embryo Transfer Conference
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• 2005.10a
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• pp.87-88
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• 2005

• Animal cells and systems
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• v.11 no.2
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• pp.191-198
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• 2007

The ultrastructure of germ cells and follicle cells during oogenesis, oocyte degeneration, reproductive cycle, and first sexual maturity in female Cyclina sinensis were investigated for clams collected from Simpo, Jeollabuk-do, Korea, by cytological and histological observations. Vitellogenesis occured by way of endogeous autosynthesis and exogenous heterosynthesis: vitellogensis occurred through a process of autosynthesis, which involves a combined activities of the Golgi complex, mitochondria, and rough endoplasmic reticulum. The process of heterosynthesis involved endocytotic incorporation of extraovarian precursors into the basal region of the early vitellogenic oocytes prior to the formation of vitelline envelope. The follicle cells appear to play an integral role in vitellogenesis and oocyte degeneration, functioning in phagocytosis and digestion of products originating from the degenerated oocytes: these functions can permit the transfer of yolk precursors needed for vitellogenesis. Follicle cells might have a lysosomal system for breakdown and might also resorb phagosomes in the cytoplasm for nutrient storage during oocyte degeneration.